It is known practice to improve the dissipation of heat from electrical operating means using cooling ribs. Generally, the cooling ribs are integrally molded onto the metal housing of the operating means in question, for example switchgear, in order to achieve good transfer of heat in this manner. This improved dissipation of heat allows either higher current loading for the operating means or allows a saving on electrically conductive material. A drawback of these cooling ribs molded on directly is that some of the on electric current flowing through the operating means also flows through the cooling ribs as a result of current displacement effects and additionally heats them. To dissipate this additional heating, a certain proportion of the cooling capacity of the cooling rib is needed. Accordingly, to provide this additionally required cooling capacity, the cooling ribs need to be given larger dimensions. The result of these enlarged cooling ribs is that the dimensions of the operating means are increased at the same time, and hence this operating means is made more expensive.